Automatic climate control problems

[albi1cnobi1]

Press and hold the "Off" button and then press the "Floor" button. Release those and quickly press the "Automatic" button. That gets you into the diagnostics. When you're all done make sure to press the "Defrost" button to clear the unit from test mode.

 

[thevichas]

diagnostic info ?

• If any DTCs appear during the self-test, follow the diagnostics procedure given under ACTION for each DTC given.

• If a condition exists but no DTCs appear during the self-test, refer to the Symptom Chart Condition: The EATC System Is Inoperative, Intermittent or Improper Operation.

Where do i find this information?

 

[Ranger Rick]

It's been a while since I posted an update on this, but there hasn't been much to update. At least not in terms of resolution.

I spoke with a guy yesterday that runs a shop locally that specializes in AC service. He seemed surprised that the head unit did nothing at all, coupled with the fact that the replacement unit also did nothing. He said that it would likely take multiple hours of diagnostic work to identify the issue, with a shop rate $90/hr. He seemed to hint around that he wouldn't think that the cost was justified for the vehicle.

Anyway, my last option, it would seem, is to pull the parts needed to convert the system to a basic manual-AC that most of these vehicles have. I think I'll be off to the junkyard in the morning. The info that was posted earlier here regarding swapping in the EATC system ought to serve as a reasonable guide for what to do in reverse...

 

[RomeovilleIL]

Rereading the older posts, I get the feeling you really do have a wiring problem. The issue of suddenly getting no responses after plugging/unplugging and having multiple head units inoperable seems to pretty much nail that one down. However, my guess would be not that a power wire is bad but instead one or more of the grounds between the plug and the gem. Rather than trying to chase through that mess of wires, at this point I would head to a yard and pull a wire set from another vehicle with working EATC.

 

[Ranger Rick]

I'm thinking along those line too. To sum up what I've experienced: the EATC issue started with intermittant fan operation. I replaced the fan controller, to no avail. So I swapped head units, and in so doing, no head unit since plugged in has operated correctly. However, it is powered, at least in part. The lights come on, and after about 10 minutes of operation, random bits of the LCD light up. This is true for when I replaced the head unit, and for when I put the original back in again. The random lighting is the extent of what it does; at this point it will not enter diagnostic mode either, nor will the rear fan operate anymore.

To be clear, the original at least outwardly appeared to function correctly before pulling it out, even though I didn't have complete system operation. Also of note, prior to swapping the EATC, the message center worked fine. After, not at all. I know they're tied together, so that is suggestive as well.

So, I agree, that does seem to suggest that there's a issue in how the EATC head unit was connected. Or, at least, with the wiring that it plugs into and it was disturbed when I messed with it. Maybe the best fix is to find a replacement for the dash harness, or the EATC portion. The trouble is that Explorers with EATC don't commonly appear in the junkyards. There are too few of them with the option, it would seem. I don't particularlly want to give up on the system, but I'm not sure how many choices I have.

 

[budwich]

You might want to get a meter and verify that you have voltage (and grounds) appropriate as someone was nice enough to post that information for you. Then go from there.

 

[CDW6212R]

The EATC head units are not last forever devices, nor are any that you find anywhere.

They all will have failures of certain components inside, just from age. If you suspect an issue with the EATC head unit, don't waste money on another used model. Have the one you have repaired.

Owners of Mark VII's have known for many many years that the capacitors at the least are the cause of symptoms with their EATC units, the overhead consoles, the radios, and the message center.

The Explorer/Mountaineer has those same devices as options, thus it is very likely that they all will begin to malfunction more and more over time. Find a repair service for those devices, pay some feasible amount to return them to like new condition.

 

[Ranger Rick]

You might want to get a meter and verify that you have voltage (and grounds) appropriate as someone was nice enough to post that information for you. Then go from there.

I took your advice and pulled it apart after I got home from work. In testing the plugs, I found that pins #2 & 3 on connector C297 (nonswitched 12V & main ground) don't seem to be working. I have power to the switched 12V pin, but none to the always-hot pin. And the ground didn't seem to carry a load when I connected a 12V source to it. So, tomorrow I'll see if I can make some temporary test jumpers to see if that'll allow the system to work.

I'm not holding my breath at this point, but it's at least progress. Also, when I tested the ground pin for the blend door actuator, the message center display (which as previously mentioned went dead at the same time) came back on. So, maybe there's cause for cautionary optimism. We'll see.

Regarding having the head unit repaired, I agree it would be a good thing to do, but I'm not sure how or where to take it for that sort of thing. I've seen people advertise repairing them, but the service was limited to replacing the seals on the vacuum manifold. They didn't touch the actual electronics...

 

[budwich]

glad to hear that you appear to be making progress. In my "travels" especially on this forum, I find that a lot of problems can be readily resolved by relatively simple tests of things (ie. voltage, resistance, continuity) that most people can carry out with a $5 meter and easily get to the bottom of their issues. Good luck.... you likely have a broken wire / blown fuse... you just have to find them. As you have found, just replacing a unit doesn't actually deal with wiring / connector / fusing issues which are significant in a vehicle subjected to all kinds of "environments".

 

[Ranger Rick]

Well, now the question that I have is: is there a specific fuse for the EATC system in the fuse panel? I don't have an owners manual for the vehicle, so I can't look it up readily. I had started checking through the fuses, but it takes a while without any guidance.

 

[budwich]

I think you need to refresh yourself with this thread... all the information about wiring you need has been posted.

 

[Ranger Rick]

Sorry, I didn't realize that the wiring diagram identified the fuse numbers.

 

[gonenuke]

You can get your owners manuals here Dead Link Removed

 

[Ranger Rick]

OK, here's what's new in the last 10 minutes (I have the laptop out in the Mountaineer while diagnosing). Yesterday, I was checking the wrong plug. I was going on the color description on the plug pin-out diagram to ID C297 and C298, but that was backwards from the actual once I compared the minor differences in plug shape. I still, however, had no 12V non-switched power. That led me back to the fuse panel, and I did find that the fuse #36 was blown. I switched it out, and the EATC panel is on, my rear fan panel works, and my message center came back. I have to say, I feel real stupid for putting up with a non-functioning climate control system all winter having over looked the dumb fuse.

OK, but now I'm back to my original problem - I still have no main blower fan. I have replaced the fan control module. I just tried swapping a different fan relay in the underhood box, and that didn't seem to help either. I suppose my next step is to check the fan motor itself...

 

[budwich]

It appear that you didn't really take my posts to heart or to head for that matter... get your meter out find out what the electrical conditions are based on the info posted in this thread... then will be able to easily figure out what your next step is or provide information to those on the forum.... or you could just buy some more parts..... ???

 

[Ranger Rick]

Well, that's what I'm trying to do, although I admit overlooking one of the fuses involved. Perhaps I'm just not as efficient about the process as you are. With the relay, I simply borrowed the ABS one since it was same style/pinout. I've checked the blower motor connection - I do have power there. I borrowed a multimeter. With the EATC off, there's just a couple mV on the plug. With MAX AC on, I have 14.3V, and just in normal AC mode there's about 7V. So, I'm guessing that is what I would expect to see. The AC system is operating; I hear the compressor (which clatters a little bit) and the AC hardlines are getting chilled. So would a correct conclusion be a faulty blower motor itself? Or is there something else to check before drawing that conclusion?

 

[budwich]

OK... but none of your post about the fan motor indicated any value or meter testing... just a bunch of swapping... hence my comment.

did you check to see if the blower relay was operating?... was there voltage going in to it and leaving if it was operated. The circuit diagram is relatively simple. The blower relay operates by the grounding from the controller. When it operates voltage passes thru it towards the motor. Hence, the conditions you need to check are those that I have outlined.

Yes your blower motor could be bad but you have given little indication that you have done appropriate checks to determine the conditions of the various parts of the circuits. Keep testing.... borrowed or not ... ... IF you have money for a "don't know if the motor is bad" replacement motor, you have the $5-10 for your own meter and then you can use it for as long as you want, when you want.

 

[CDW6212R]

Good advice.

I need to do that wiring/circuit research for my Mark VII. I'd like to install the Explorer(1997) EATC into the Lincoln to replace the old and not very user friendly EATC. I need to find out if the blend door actuator signals and blower motor controls will work. That is a wiring issue, do the on paper work before spending extra money.

 

[Ranger Rick]

I did probe the contacts for the relay, however I couldn't really get into the terminals of it with the relay in place to verify that there was current out of the relay on the appropriate terminal. I could, however, feel the relay click on and off when it was cycled. Also, at the end of the day, I still have variable voltage at the blower motor plug. Would that not combine to conclude that the relay was working? If I have variable voltage that's tied to the command of the EATC at the blower motor, what else would I look for to check?

 

[budwich]

IF you look at the circuit (in this thread), there is no variable voltage going to the blower motor plug... probably the only conclusion one could draw is that perhaps there is a "testing problem".... :-(


Now I got supper in me... last thing to do... pull connector on the motor.... carefully run a jumper from the battery on one side of the motor and a ground wire on the other side... does the motor run???